Cargo container latch

ABSTRACT

A retractable cargo container latch assembly for securing cargo containers or pallets to the seat-tracks in the floor of an aircraft compartment wherein the latch mechanism comprises a pair of rotatable latch arms, each having a vertical restraint lip integral therewith in combination with a spring-loaded pawl for securing the latch-head assembly in the upright extended cargo engaging position.

United States Patent [I91 Alberti Mar. 12, 1974 CARGO CONTAINER LATCH3,210,038 lO/l965 Bader et al. IDS/369 x Invsntor: J Alberfi, at e, as3.262588 7/[966 Davldson 244/137 R X [73] Assignee: The Boeing Company,Seattle, Primary ExaminerDuane A. Reger Wash. Assistant Examiner-GregoryW. OConnor Filed: y I972 Attorney, Agent, or FzrmHv Gus Hartmann; GlennOrlob [21] Appl No; 274,128

[57] ABSTRACT [52] US. Cl... 244/118 R, 244/l37 R, 248/119 R Aretractable cargo container latch assembly for se- [51 Int. Cl. B64c1/20 Curing Cargo Containers or Pallels the Seat-tracks [58] Field ofSearch 244/1 13 R, 137 R; the floor of an aircraft compartment whereinthe latch 105/369 A mechanism comprises a pair of rotatable latch arms.each having a vertical restraint lip integral therewith [56] ReferencesCited in combination with a spring-loaded pawl for securing UNITEDSTATES PATENTS the latch-head assembly in the upright extended cargo$377,040 Mums Hansen 244/118 R x engagmg posmon' 3,251,489 5/1966Davidson 244/137 R X 2 Claims, 16 Drawing Figures PAIENIEDm 12 1973796.39?

it III I ll CARGO CONTAINER LATCH SUMMARY OF THE INVENTION The inventionrelates to a cargo container or pallet latch assembly for securing thecargo loaded container pallets to the floor of an aircraft cargo storagecompartment and more particularly to a simplified latch mechanism havinga minimum number of parts for providing the required functions includingretractability to a flush floor mounted position. The latch assembly ofthe present invention could be utilized in a cargo handling system suchas described in my co-pending application Ser. No. 140,773, filed May 6,1971. As more clearly described therein, during the cargo loadingoperation, a powered drive wheel system engages the undersurface of thecargo containers and in combination with guide devices, arranges andaligns the cargo containers into their approximate position within thestorage compartment of the aircraft. As each of the cargo containers ismoved into final position, the retracted latch assembly of the presentinvention, is raised to the upright extended position for engaging theflanged base or a pocket in the container for vertical and lateralrestraint.

Rapid turn around time of an aircraft is essential to a profitableoperation and the time saved, particularly in the area of cargo loadingand unloading operations where a greater portion of the time savings canbe realized, is of utmost importance to the utilization schedule of theaircraft. Therefore, ease and simplicity of operation of the individualcomponents comprising the cargo handling system together with lowmaintenance are prerequisites to savings and the present invention withits case of operation and simplicity in design wherein a minimum numberof parts are utilized while still retaining all of the necessaryfunctions of the more complicated mechanisms, makes it a mostadvantageous device for such a system.

FIG. I is a plan view of the aircraft cargo container retractable latchassembly of this invention with the latch-head assembly shown in theupright extended position for restraining the cargo containers;

FIG. 2 is a side view of FIG. I;

FIG. 3 is a sectional view taken along the line 3-3 in FIG. 2;

FIG. 4 is a sectional view taken along the line 4-4 in FIG. 2;

FIG. 5 is an enlarged side view of the latch-head assembly in theextended upright position similar to the showing in FIG. 2;

FIG. 6 is a plan view of the cargo container latch assembly with thelatch-head assembly shown in the retracted position for unrestrainedmovement of the cargo container thereover;

FIG. 7 is a side view of FIG. 6;

FIG. 8 is an enlarged plan view of the latch-head assembly in theretracted position similar to that depicted in FIG. 6;

FIG. 9 is a sectional side view of the latch-head assembly taken alongthe line 9-9 in FIG. 8;

FIG. 10 is an enlarged side view of the inner latch arm 35;

FIG. 11 is a rear view of the inner latch arm 35 taken in the directionindicated by ll-ll in FIG. 10;

FIG. 12 is an enlarged side view of the outer latch arm 34;

FIG. 13 is a front view of the outer latch arm 34 taken in the directionindicated by l3l3 in FIG. 12;

FIG. 14 is an enlarged side view of the pawl member 50;

FIG. 15 is a front view of the pawl 50 taken in the direction indicatedby 15-15 in FIG. 14; and

FIG. 16 is an elevated rear view of the pawl 50 taken in the directionindicated by 16-16 in FIG. 14.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The cargo container latchassembly of the present invention comprises a base or carriage that ismounted to the floor of an aircraft storage compartment and is manuallyadjustable in a fore and aft direction through engagement of alongitudinal seat-track or rail in the floor. It should be noted thatwith respect to the latch assembly illustrated in the figures, that thelogical direction of loading the cargo containers into the storagecompartment would be towards the left, that is from right to left andunloading towards the right due to the direction of rotation of thelatch head assembly during extension or retraction.

The carriage of the latch assembly is provided with rollers 20 at eachend for engaging the undersurface of the cargo container to permit easeof movement of the container over the latch assembly when it is in theretracted position. The rollers 20 and the engaging cargo containerlatch head assembly 21 are rotatably mounted between the side rails 22of the carriage. Also, mounted between the side rails 22 are thecarriage to seat-track locking means or foot assembly 23 positionedtowards each end of the carriage adjacent to the rollers 20. Thecarriage lock or foot assembly 23 secures the carriage to the track (notshown) against both lateral and vertical movement and also provides forthe parallel adjustment along the track. The centrally mounted latchhead assembly 21, shown in FIGS. 6-9 in the retracted position, isrotatable counterclockwise about inner axis 24 and outer axis 25 to theupright extended position shown in FIGS. 1-5 and comprises an innerlatch arm 26 and an outer latch arm 27 pivotally mounted to the carriageside rails 22 for rotation about the inner and outer axes 24 and 25respectively. The outer latch arm 27, as more clearly shown in theenlarged detail views of FIGS. 10 and 11, has a vertical restraint lip28 for engaging a base flange or swinging into the pocket or recess inthe base of a cargo container for vertical restraint thereof. The widthof the outer arm 27, taken in the direction parallel to its rotationalaxis 24, is nonuniform in cross section as is more clearly seen in therear view of FIG. I] taken in the direction indicated by ll-ll in FIG.10. Also, as shown in FIG. 11 the central portion of the arm has acutout section wherein the inner am 26, shown in FIGS. 12 and I3,interlays. The appearance of outer lever arm 27 is that of an invertedU-shaped or forked lever arm wherein the upper end or terminus of the amhas a lateral projection or vertical restraint lip 28. The outer leverarm 27 comprises two side arm members 29, 30, where one is the mirrorimage of the other, which are integrally interconnected by a centralportion 31. When both the inner latch arm 26 and the outer latch arm 27are assembled in the upright extended position shown in FIGS. 1-5,further counterclockwise movement of the inner arm 26 therefrom, isrestricted by its back surface 32 contacting or abutting the outer leverarm 27 against its back surface in the central portion 31. Once theinner lever arm 26 is in its farthest position, towards the left asshown in the FIGS. 1-5, retraction or clockwise rotation from thisupright extended position is restrained by a spring-loaded latching pawl33. the enlarged details of which are more clearly shown in FIGS. l4,l5, and 16. The pawl 33 comprises two identically shaped side members34, 35 with an integrally interconnected central portion 36. The crosssectional shape of the central portion 36 and its projection continuedinto the side members 34, 35, constitutes the pawl engaging projectingmember 37. This member effects the interlocking of the inner and outerlatch arms 26, 27 that comprise the latch head assembly as shown in theenlarged view of FIG. 5. In the latch head assembly, the pawl 33 has acentral cut-out section or space between the two side members 34, 35,that permits the side members of the pawl to straddle the inner latcharm 26. The pawl 33, through a helical compression spring 38, is biasedto locking the latch head assembly in the upright extended position bypositioning the pawl engaging projecting member 37 into engagement withthe detent 39 on the inner latch arm 26. In FIGS. 2 and 3, release ofthe latch head assembly is effected by manually rotating the pawl 33clockwise with sufficient force to overcome the pressure of the springs38 which tend to force the pawl to the left or counterclockwise. As moreclearly shown in FIGS. 14-l6, the pawl side members 34, 35 have anintegral tail 40 which is approximately at right angles to the pawlengaging projecting member 37 and a slight thumb pressure against thistail 40 will compress the springs 38 which bear at one end against theinner side of the pawl in the spring retaining recess 41 and at theother end against the under surface of a shoulder that is on the insideof side arm members 29, 30 FIGS. and ll. The pawl 33 is pivotallymounted on the same shaft as the outer latch arm 27 and is rotatableabout the outer axis 25. Also, the pawl is mounted for limitedrotational movement with respect to the outer latch arm 27 because thepawl side members 34, 35 are positioned to operate in the cutout sectionon the interior side of the side arm members 29 and 30, FIGS. 10 and l LIn FIGS. 6-9, when the latch head assembly is in the retracted positionand is to be raised to the upright extended position, because of theoverlying relationship of the inner latch arm 26 over the outer latcharm 27, it is preferable to initially raise the outer latch arm 27 sinceits counterclockwise rotation will carry with it the inner latch arm 26which is in an intermeshing relationship therewith. Also, as the outerlatch arm 27 is raised from the retracted position, it carries with itthe springloaded pawl 33. This can be more clearly seen from a side viewof a pawl side member shown in FIG. 14 superimposed on to the side viewof the outer latch arm 27 shown in FIG. 10. From this visualsuperimposition, it will be noted that with the axes of rotation of thepawl 33 and the outer latch arm in alignment, that the rotationalmovement of the pawl 33 with respect to the outer latch arm 27, isrestricted within the cutout area provided on the inside surface of theouter latch arm 27. Clockwise rotation of the pawl 33 with respect tothe outer latch arm 27, is limited by the abutment engagement ofsurfaces on each member, namely: 42 on the outer latch arm 27 and 43 onthe pawl 33. Also,

these two surfaces are spring biased to the spread position.counterclockwise rotation of pawl 33, with respect to the outer latcharm 27, is limited by the pawl engaging projecting member 37 contactingsurface 44 of the outer latch arm 27. The amount of relative movementbetween the pawl 33 and the outer latch arm 27 is determined, as shownin FIG. 12, by the depth of the detent surface 39 on the inner latch arm26. As a result of the small amount of relative movement, the springs 38will deflect a small amount. This configuration thus allows the use of apair of small but effective compression springs. For lowering the latchhead assembly, as previously described, the pawl 33 is rotated clockwisewith respect to the outer latch arm 27 about the axis 24 until the pawlengaging projecting member 37 is clear of the detent 39 on the innerlatch arm 26; at which time, both the inner and outer latch arms 26, 27,can be rotated to the down position.

What is claimed is:

l. A cargo container latch assembly for an aircraft storage compartmentcomprising: a carriage having a pair of parallel sides; first and secondhook arms pivotally mounted between the sides for rotation about an axistransverse to the sides and with their axis of rotation parallel; saidfirst and second hook arms being movable from a retracted andinoperative cargo restraining position to an erected cargo engagingposition whereat they are in a crossed relationship with their hookportions facing in opposite directions and outwardly of each other; saidfirst hook arm having an opening in its width taken in the directionparallel to its rotational axis through which the second hook arm passeswhen both hook arms are rotated to their erected position, a springbiased latching pawl connected to said first hook arm for rotationtherewith and having a width taken in the direction parallel to therotational axis of said first hook arm for spanning the opening in thefirst hook arm through which the second hook arm passes abutment meansfor limiting relative rotation of said spring biased latching pawl withrespect to said first hook arm such that rotation of said first hook armcauses said pawl to engage the second hook arm for simultaneouslyrotating in the same direction, both hook arms from their retracted totheir erected position whereat, the pawl is spring biased into a latchedrelationship with the second hook arm for restraining both hook armsfrom rotation about their respective axes.

2. A retractable cargo container latch assembly having a base that isfastened to the floor of an aircraft storage compartment, said basebeing manually adjustable in a fore and aft direction by lockingengagement with a longitudinal track in the compartment floor, saidcargo latch assembly comprising: first and second hook arms pivotallymounted to the base for rotation about an axis transverse to thelongitudinal axis of the aircraft and having their hook portions facingoppositely and outwardly of each other; the second hook arm having itsaxis of rotation parallel to and longitudinally spaced apart from theaxis of rotation of the first hook arm; the axis of rotation of eachhook arm being positioned with respect to each other such that the hookarms are in a crossed relationship when rotated to an upright extendedposition for engaging a cargo container; said first hook arm having acentral cut-out portion in its width taken in the direction parallel toits rotational axis through which the second hook arm passes when armthrough which the second hook arm passes such that rotation of saidfirst hook arm from the retracted position to the erected position,causes the spring hiased pawl to engage the second hook arm for rotatingboth hook arms together in the same direction to their erected positionwhereat the pawl is spring biased into a latched relationship with thesecond hook arm for re straining both hook arms from rotation abouttheir respective axis.

1. A cargo container latch assembly for an aircraft storage compartmentcomprising: a carriage having a pair of parallel sides; first and secondhook arms pivotally mounted between the sides for rotation about an axistransverse to the sides and with their axis of rotation parallel; saidfirst and second hook arms being movable from a retracted andinoperative cargo restraining position to an erected cargo engagingposition whereat they are in a crossed relationship with their hookportions facing in opposite directions and outwardly of each other; saidfirst hook arm having an opening in its width taken in the directionparallel to its rotational axis through which the second hook arm passeswhen both hook arms are rotated to their erected position; a springbiased latching pawl connected to said first hook arm for rotationtherewith and having a width taken in the direction parallel to therotational axis of said first hook arm for spanning the opening in thefirst hook arm through which the second hook arm passes abutment meansfor limiting relative rotation of said spring biased latching pawl withrespect to said first hook arm such that rotation of said first hook armcauses said pawl to engage the second hook arm for simultaneouslyrotating in the same direction, both hook arms from their retracted totheir erected position whereat, the pawl is spring biased into a latchedrelationship with the second hook arm for restraining both hook armsfrom rotation about their respective axes.
 2. A retractable cargocontainer latch assembly having a base that is fastened to the floor ofan aircraft storage compartment, said base being manually adjustable ina fore and aft direction by locking engagement with a longitudinal trackin the compartment floor, said cargo latch assembly comprising: firstand second hook arms pivotally mounted to the base for rotation about anaxis transverse to the longitudinal axis of the aircraft and havingtheir hook portions facing oppositely and outwardly of each other; thesecond hook arm having its axis of rotation parallel to andlongitudinally spaced apart from the axis of rotation of the first hookarm; the axis of rotation of each hook arm being positioned with respectto each other such that the hook arms are in a crossed relationship whenrotated to an upright extended position for engaging a cargo container;said first hook arm having a central cut-out portion in its width takenin the direction parallel to its rotational axis through which thesecond hook arm passes when both hook arms are rotated to their erectedposition; a pawl pivotally mounted on the rotational axis of the firsthook arm; stop means between the pawl and the first hook arm forlimiting rotational movement of the pawl with respect to the first hookarm; spring means biasing said stop means such that rotation of thefirst hook arm substantially imparts a like rotation to the pawl; saidpawl having a width taken in the direction parallel to the rotationalaxis of said first hook arm for spanning the central cut-out portion inthe first hook arm through which the second hook arm passes such thatrotation of said first hook arm from the retracted position to theerected position, causes the spring biased pawl to engage the secondhook arm for rotating both hook arms together in the same direction totheir erected position whereat the pawl is spring biased into a latchedrelationship with the second hook arm for restraining both hook armsfrom rotation about their respective axis.